Journal
POWDER TECHNOLOGY
Volume 356, Issue -, Pages 759-768Publisher
ELSEVIER
DOI: 10.1016/j.powtec.2019.09.023
Keywords
Additive manufacture; Metal powder; Gas atomization; Melt nozzle; Mass median diameter; Satellite particle
Categories
Funding
- Beijing Nova Program [xx2018036]
- Shenzhen Key Laboratory for Additive Manufacturing of Highperformance Materials [ZDSYS201703031748354]
- Shenzhen Science and Technology Plan [JSGG20180508152608855]
Ask authors/readers for more resources
A pressure-gas atomizer was developed, in which the melts were pressurized through melt nozzles with a small inner diameter, aiming for a small mass median diameter (MMD, d(50,3)) and high productivity of fine spherical powders. The maximum melt flow resistance in a melt nozzle, defined as the sum of the capillary resistance and viscous pressure drop, was analyzed by varying the inner diameter of the melt nozzle (D-0). The calculation results indicate that the maximum melt flow resistance increases quickly with the decrease of D-0, and varies in an order of 10(0)-10(2) kPa for different metal melts when D-0 reduces from 4.0 mm to 0.5 mm. Atomization runs with three kinds of aluminium (Al) alloys were accomplished using melt nozzles with different inner diameters in a pilot plant whereby an over-pressure in a range of Delta p(i) = 30-45 kPa can be maintained on the melts to enhance the melt flowing in the melt nozzle. The experimental results indicate that the atomization efficiency can be well improved by reducing the inner diameter of the melt nozzle, which resulted in a small MMD, narrow particle size distribution and high fine powder yield. For Al-l alloy powders, when the inner diameter of the melt nozzle reduces from D-0 = 3 mm to D-0 =1 mm, the particle MMD reduces from d(50,3) = 86.13 mu m to d(50,3) = 40.42 mu m, and the powder yield <53 mu m increases from 27.60% to 62.57%. For Al-Ill alloy powders, when the inner diameter of the melt nozzle reduces from D-0 = 4 mm to D-0 = 2 mm, the particle MMD reduces from d(50,3) = 120.10 mu m to d(50.3) = 54.82 pm and the powder yield <53 pm increases from 20.70% to 48.20%. Moreover, the satellite particles and lamellae sticking on the particle surface were reduced when a melt nozzle with a small inner diameter was employed in a gas atomization process. (C) 2019 Elsevier B.V. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available